Gonorrhea's Growing Resistance to Antibiotics Concerns CDC

THURSDAY, July 7 -- Gonorrhea appears to be growing increasingly resistant to drugs called cephalosporins, the only remaining class of antibiotics available to treat the sexually transmitted disease, according to a new report.

Researchers analyzed 10 years' worth of gonorrhea samples (isolates) from men in 30 U.S. cities. The samples were collected between January 2000 and June 2010 through the U.S. Centers for Disease Control and Prevention's Gonococcal Isolate Surveillance Project.

The analysis revealed an increase in the proportion of samples with elevated minimum inhibitory concentrations (MICs), the lowest concentration of antibiotics needed to halt the growth of gonorrhea bacteria. These increases in MICs suggest a decline in gonorrhea's susceptibility to antibiotics, the researchers explained in a CDC news release.

During the study period, the percentage of gonorrhea samples exhibiting elevated MICs rose from 0.2 to 1.4 percent of samples for cefixime (an oral cephalosporin) and from 0.1 to 0.3 percent for ceftriaxone (an injectable cephalosporin).

To date, there are no recorded cases of patients with gonorrhea that couldn't be treated with these antibiotics in the United States.

The study is published in the July 8 edition of the CDC's Morbidity and Mortality Weekly Report.

The researchers called for increased efforts to develop new treatments and a boost in gonorrhea surveillance in order to identify emerging patterns of antibiotic resistance in gonorrhea as they occur.

Over time, gonorrhea has developed resistance to several antibiotics. The CDC currently recommends dual therapy of cephalosporins with either azithromycin or doxycycline. Treatment options would become substantially limited if gonorrhea becomes resistant to cephalosporins, the researchers warned.

Left untreated, gonorrhea can cause infertility in women and increase the risk of infection with HIV, the virus that causes AIDS, for men and women.

More information

The U.S. National Institute of Allergy and Infectious Diseases has more about gonorrhea.